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101.
The research reported here addresses the issues of institutional, social and land-use change with reference to land reclamation system maintenance in the Odra River Valley, SW Poland. Land reclamation systems are a network of different types of water control infrastructure and they require the collective maintenance effort of all users in order to fulfill drainage and irrigation functions properly. The example of decline in these systems in Polish rural areas brings together environmental and economic issues, as well as social dimensions of change from socialist top-down to democratic bottom-up decision-making and management. After 1989 the financing and management of land reclamation services by the State greatly decreased and a duty of LRS maintenance was actually transferred from government to individual land users. Farmers were not ready to take this responsibility and the whole system declined. The analysis presented in this article is a contribution to a better understanding of non-functioning land reclamation systems. Some recommendations for the future improvement of these systems are also provided.  相似文献   
102.
The aim of the study was to determine the response of Salix purpurea?×?viminalis L. growing on Pleurotus ostreatus spent mushroom substrate (SMS) with different copper (Cu) addition. The content of Cu in roots, leaves and shoots was reduced by SMS addition. A decrease of biomass was observed with simultaneous Cu concentration increase. SMS induced leaf and root elongation of Cu-treated plants. Variation in the profile of low molecular weight organic acids with the domination of oxalic and acetic acids was observed. The total phenolic content significantly increased for plants cultivated with SMS, while the biosynthesis of salicylic acid was considerably weakened. The content of sugars was generally reduced by SMS. Alteration in the level of the stress-related molecules suggests mitigation of the harmful effect of Cu on Salix hybrid metabolism by SMS addition. This pointed to the possibility of using SMS in contaminated soil to reduce the toxic effect of metals on plants used in phytoextraction.  相似文献   
103.
The growth of human population leads to intensification of agriculture and promotes, through eutrophication, development of cyanobacteria. One of the most widespread and bloom-forming species in freshwater is toxic Microcystis aeruginosa (M. aeruginosa). Combustion of fossil fuels and metallurgical processes are the main sources of heavy metals contamination in surface water including cadmium (Cd) and lead (Pb). The following study was conducted in order to determine the effect of 1- 20 mg. L-1 of Cd and Pb on photochemistry (using flow cytometry) and growth (based on chlorophyll concentra- tion) ofM. aeruginosa as well as to estimate levels of metal bioaccumulation. We have found that 1-10mg.L-1 of Cd and 1-5 rag. L1 of Pb induced continuous enhancement of chlorophyll fluorescence during 24 h of incubation. No significant degradation of chlorophyll was observed in these samples. At higher concentrations of 20 mg. L-1 of Cd and 10-20 mg.L-1 of Pb chlorophyll level significantly decreased and its fluorescence was quenched. M. aeruginosa demonstrated high capability of Cd and Pb bioaccumulation, proportionally to initial metal concentration. In samples with initial concentration of 20 mg. L-1 of Cd and Pb bioaccumulation of 87.3% and 90.1% was observed, respectively. Our study demonstrates that M. aeruginosa can potentially survive in highly metals polluted environments, be a primary source of toxic metals in the food chain and consequently contribute to enhanced toxicity of heavy metals to living organisms including human.  相似文献   
104.
The aim of this work is to investigate the application of fly ash adsorbent for removal of arsenite ions from dilute solution (100–1,000 ppm). Experiments were carried out using material from the “Turów” (Poland) brown-coal-burning power plant, which was wetted, then mixed and tumbled in a granulator to form spherical agglomerates. Measurements of arsenic adsorption from aqueous solution were carried out at room temperature and natural pH of fly ash agglomerates, in either a shaken flask or circulating column, to compare two different methods of contacting solution with adsorbent. Adsorption isotherms of arsenic were determined for agglomerated material using the Freundlich equation. Kinetic studies indicated that sorption follows a pseudo-second-order model. Preferable method to carry out the process is continuous circulation of arsenite solution through a column.  相似文献   
105.
Environmental Science and Pollution Research - Phytoremediation, as a cost-effective, highly efficient, environmentally friendly, and green approach, gained attention to the removal of metals,...  相似文献   
106.
The possibilities of application of a three-step system combining hybrid biological treatment followed by advanced UV/O3 oxidation with in situ generated O3 and membrane separation (ultrafiltration (UF) and nanofiltration (NF)) to treat and reuse the wastewater from an industrial laundry are presented. By the application of a hybrid moving bed biofilm reactor (HMBBR), the total organic carbon concentration was reduced for about 90 %. However, since the HMBBR effluent still contained organic contaminants as well as high concentrations of inorganic ions and exhibited significant turbidity (8.2 NTU), its further treatment before a possible reuse in the laundry was necessary. The UV/O3 pretreatment prior to UF was found to be an efficient method of the membrane fouling alleviation. During UF, the turbidity of wastewater was reduced below 0.3 NTU. To remove the inorganic salts, the UF permeate was further treated during NF. The NF permeate exhibited very low conductivity (27–75 μS/cm) and contained only small amounts of Ca2+ and Mg2+; thus ,it could be reused at any stage of the laundry process.  相似文献   
107.
This study aims to determine changes in the structure of cryptogamic vegetation of poor psammophilous grassland along a pollution gradient near a zinc smelter to evaluate the potential of species assemblages as bioindicators of soil condition. Lichens and bryophytes were examined in study plots along six transects in four distance zones, and the physicochemical properties of corresponding soil samples were analysed. Four different responses of species to substrate contamination were identified, with a distinct group of species resistant to and favoured by metal contamination. Although species richness decreases as one approaches the smelter, the gradual replacement of certain sensitive species by resistant ones was observed along the pollution gradient. The results enabled us to develop a useful tool to diagnose strongly polluted sites. Two different cryptogamic assemblages of well-recognised key species characteristic for strongly polluted and lightly polluted sites were distinguished. We conclude that cryptogamic community structure clearly corresponds to the degree of soil contamination, thus demonstrating high bioindicative value. The study confirmed the high relevance of the community approach in metal pollution biomonitoring.  相似文献   
108.
Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling.The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification.The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives.One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with flotation sewage sludge, and 45% v/v and 5% v/v, respectively, for precipitation sewage sludge. These combinations allowed for obtaining products with negligible heavy metal leaching levels and hardness similar to commercial glass, which suggests they could be potentially used as construction aggregate substitutes. Incineration of sewage sludge before the vitrification process lead to increased hardness of the vitrificates and reduced leaching of some heavy metals.  相似文献   
109.
Lanthanum-modified TiO2 photocatalysts (0.2–1.5 wt% La) were investigated in the methanol decomposition in an aqueous solution. The photocatalysts were prepared by the common sol-gel method followed by calcination. The structural (X-ray diffraction, Raman, X-ray photoelectron spectroscopy), textural (N2 physisorption), and optical properties (diffuse reflectance spectroscopy, photoelectrochemical measurements) of all synthetized nanomaterials were correlated with photocatalytic activity. Both pure TiO2 and La-doped TiO2 photocatalysts proved higher yields of hydrogen in comparison to photolysis. The photocatalyst with optimal amount of lanthanum (0.2 wt% La) showed almost two times higher amount of hydrogen produced at the same time as in the presence of pure TiO2. The photocatalytic activity increased with both increasing photocurrent response and decreasing amount of lattice and surface O species. It has been shown that both direct and indirect mechanisms of methanol photocatalytic oxidation participate in the production of hydrogen. Both direct and indirect mechanisms take part in the formation of hydrogen.  相似文献   
110.
Environmental lead poses a serious threat for public health, particularly, for children. The use of substances with metal-binding properties, such as natural alginates, may be a potentially effective method for elimination of toxic metal ions from human body. In present study, effect of calcium alginate isolated from brown algae on distribution of the lead ions in preschool children was investigated. In the beginning of the study, lead concentration in urine, feces, and hair was determined. Then these children were administered a dietary supplement containing calcium alginate for four weeks. The results showed that all children participated in the study had a high baseline median lead level in urine (1.1 µg/L), feces (4.6 µg/g), and hair (5.0 µg/g). Administration of calcium alginate resulted in twofold increase of the urine lead level within two weeks from the start of the treatment. At the end of alginate administration, significant decrease of lead concentration in hair was registered. These results suggest that calcium alginate can potentially prevent accumulation of the lead ions in the body and may be used as an active agent for elimination of this toxic metal from human body.  相似文献   
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